<AWT Dev> [9] Review Request: 8029253 [macosx] Performance problems with Retina display on Mac OS X

[Sergey Bylokhov]

Hello.
Please review the fix for jdk 9, which is also targeted for jdk 8u20.
Description:
We have two codepaths to draw a raster to the opengl:
  - via glDrawPixels
  - via intermediate texture.
We empirically checked, what way is better, based on benchmarks. Became 
obvious that on intel devices the glDrawPixels is slower than 
intermediate texture, and this is a bottleneck when the scrolling is used.

j2bench is not properly cover retina case, but according to some of my 
tests results is 2-3 times better.

There is no regressions on windows:
Summary:
   ogl-base:
     Number of tests:  60
     Overall average:  1452524.357368045
     Best spread:      0.17% variance
     Worst spread:     248.44% variance
     (Basis for results comparison)

   ogl-fix:
     Number of tests:  60
     Overall average:  1469528.5484618822
     Best spread:      0.12% variance
     Worst spread:     246.59% variance
     Comparison to basis:
       Best result:      161.48% of basis
       Worst result:     93.54% of basis
       Number of wins:   38
       Number of ties:   17
       Number of losses: 5

http://cr.openjdk.java.net/~serb/8029253/perf/windows.txt

Bug: https://bugs.openjdk.java.net/browse/JDK-8029253
Webrev can be found at: http://cr.openjdk.java.net/~serb/8029253/webrev.00

-- 
Best regards, Sergey.